This invention relates to a dispensing head for a dispenser which is pressurized by squeezing the sides of the container. More particularly, the invention is directed to a dispensing head in which air and liquid are mixed to produce a fine spray, and in which there is a push-pull type valve arrangement for sealing off the dispensed liquid from the atmosphere when the dispenser is not in use.
Although squeeze bottle type sprayers have been used for many years, such sprayers were largely replaced for a long period of time by pressurized can dispensing systems. One squeeze bottle dispenser which has come into use as a substitute for pressurized cans is described in U.S. Pat. Nos. 5,183,186 and 5,318,205. These patents show a squeeze bottle dispenser in which an air passageway and a product (i.e., fluent material) passageway meet in a tapered mixing chamber. In the device of that invention, the tapering of the mixing chamber direct the air flow at an angle to the flow of liquid, resulting in turbulence in the liquid in the mixing chamber. This turbulence breaks the liquid up and intimately mixes it with the air. As a result, a fine spray is propelled out of the orifice.
The disadvantage of this invention is that it requires the use of a relatively expensive ball valve for the liquid outlet, and liquid will leak out of the dispenser when the bottle is inverted, because the air path is completely open to fluid flow. Furthermore, in this arrangement, the outlet orifice and the air vent path allow air to be in continuous contact with the liquid to be dispensed. This can result in drying of the liquid substancexe2x80x94disadvantageous result which can clog the outlet orifice and prevent proper spraying.
Another patent relating to squeeze bottles is U.S. Pat. No. 5,273,191. That patent also describes a squeeze bottle using a tapered mixing chamber for mixing air and liquid. In that patent, various valving arrangements are shown, including valved gaskets for controlling the flow of liquid to the mixing chamber and for controlling the flow of air to the mixing chamber and into the squeeze bottle. In addition, that patent shows a biased valve element which opens and closes the liquid passage in response to the pressure in the liquid passage.
A dispensing head for a dispenser with a push-pull type valve arrangement is disclosed in U.S. patent application Ser. No. 09/073,615, now U.S. Pat. No. 6,050,504 which is incorporated by reference. In that invention, a squeeze bottle has a liquid flow path and an air flow path. When the bottle is squeezed, liquid is transmitted through the liquid flow path and pressurized air through the air flow path. These two flows meet in a mixing chamber which is located adjacent to an outlet orifice. The air and liquid mix to form a fine spray. The disadvantage of this invention is that the pull knob is located opposite the outlet orifice. Furthermore, this invention allows air to be in continuous contact with the liquid to be dispensed.
It is an object of the invention to provide a spray dispensing device for use with a non-pressurized container, such as a squeeze bottle, which utilizes a push-pull type valve, with the pull knob located on the same side as the outlet orifice.
It is a further object of the invention to provide a valve which prevents the infiltration of air into the internal passages of the dispenser.
In accordance with the invention, a spray dispenser is provided having a dip tube which can extend into a container, such as a squeeze bottle, holding a quantity of liquid. The top of the dip tube is connected to a ball-check valve assembly having a ball which ordinarily rests on top of a conduit of restricted diameters. An air passage in the spray dispenser can connect the inside of the bottle with a mixing chamber in the dispenser. A separate product passage leads from the top of the ball-check to a mixing chamber and is directed toward a spray orifice in the mixing chamber. The air passage is an annular passageway which is concentrically disposed around a portion of the product passage leading to the mixing chamber.
When the bottle is squeezed, the resulting pressure build up forces air into the mixing chamber and liquid up the dip tube. The liquid forces the ballcheck to open and the liquid is directed toward the mixing chamber. Simultaneously, air is forced through the annular air passage. The stream of air converges and impinges upon the core stream of liquid when deflected by tapered walls of the mixing chamber. This causes an atomization of the liquid and a fine spray is expelled through the orifice.
As the pressure in the bottle is relieved, the ball drops down back onto the conduit of restricted diameter thereby trapping product in the dip tube. Thus, the product will be retained in the dip tube at a high level, above the liquid level in the bottle, ready for the next squeeze cycle. In this way, the lag time which ordinarily occurs prior to spraying is eliminated.
The product passage is formed in a valve which is housed in a body of the spray dispenser. The valve may advantageously be formed as a push-pull valve which opens and closes the air and product passageways. In a closed position of the valve, both the product and air passageway are completely closed to the inside of the squeeze bottle, thereby preventing air from entering the inside of the squeeze bottle. The closing off of the passageways therefore reduces potential drying of the liquid product in the squeeze bottle.
It is a further advantage of the push-pull valve of the present invention that it may be operated by a knob located on the same side as the outlet orifice. Consumers are particularly familiar with valves that operate in such a manner from such product dispensers as liquid dish detergent bottles.
It is a further object of this invention to provide an improved snap on connection for fastening the spray housing to a neck of a bottle. In accordance with this object, the spray housing is provided with a flexible skirt which extends into an annular groove on the bottle. The annular groove exerts a radial force on the flexible skirt, which provides additional locking power for the snap on connection.
Advantageously, this allows the skirt wall to be made of thinner material, yet still provide sufficient locking power. Since the skirt wall can be made of thinner material, the neck can be manufactured with larger tolerances and the spray housing can still be mounted over the neck without requiring excessive force to push the dispenser housing over the neck. The larger tolerances allow the bottles to be made in various production plants worldwide. Furthermore, because the skirt is combined within the annular groove, the bottle/spray dispenser combination is more tamper resistant than traditional designs.
Further objectives and advantages of the subject invention will be apparent to those skilled in the art from the detailed description of the disclosed invention.